Code for sustainable homes: case studies volume 2 - Gov.uk

More documents

Recommendations

Info

The inclusion of renewable energy in both the houses and flats was the other key way in which the developer’s standard specification was changed to order to achieve the energy credits. Using solar thermal hot water on the houses and photovoltaics on the flats was a deliberate decision by the developer to ensure the best end use of the energy produced. In the two blocks of flats owned by the housing association, the energy produced by the photovoltaic panels will be divided between all the units in the block. As the housing association will own the building they will be able to ensure that the communal solar photovoltaic system is optimally maintained. In the block containing the four Code Level 3 shared ownership dwellings alongside private flats that were not assessed using the Code, the photovoltaic system has been directly connected to the four units in order to ensure the 25 per cent improvement in dwelling emission rates is achieved for only those units. The hot water produced by the solar thermal hot water panels will be used by a single house only. Both solar technologies will contribute to reducing tenants’ energy bills as well as their carbon emissions, either directly or indirectly via the housing association. While the performance of this development will not be monitored, the developer will be able to monitor the performance of future Code developments using Smart meters as part of a company wide agreement with an energy supplier. The developer felt this was essential to understand actual performance versus designed performance, and improve future designs, particularly where other low or zero carbon energy technologies were specified. The developer felt that while Code Level 3 was achievable through minor changes to the specification on standard houses and flats on this development, it has been more challenging on other sites where there are different site conditions, planning requirements and local authority services. It would be more challenging to cost effectively reach Code Level 4 and above using the design and construction methods used on this site, and would probably entail a completely different approach for the energy credits. All build systems have conventional building warranties. The boiler in the flats 30 | CODE FOR SUSTAINABLE HOMES | CASE STUDY 7
WORKING WITH THE CODE FOR SUSTAINABLE HOMES This is one of the first developments on which either the developer or the housing association has achieved Code certification. Given that the houses and flats are based on standard houses types, there have been limited challenges to overcome by the developer to achieve Code Level 3. The site allowed the developer to gain good ecology credits due the condition of the site pre-development and planning requirements. A planning requirement for Lifetime Homes meant that all four credits within the Code were awarded, though the developer may have wished to utilise other methods of reaching Code Level 3 in this particular instance. Because the design was adapted from an existing set of plan types, the space impacts for meeting the Lifetime Homes requirements were greater than in schemes developed from scratch and equate to approximately an additional 5–10 per cent of total floor area in each unit. The developer sought to maximise the use of cost effective design and specification to achieve Code credits, including: low energy lighting, recycling bins in kitchens, provision of drying lines in gardens and/or bathrooms, provision of home office space and the use of water butts in gardens. The credit obtained by registering the site under the Considerate Constructors Scheme (CCS) was also considered to be an easy win. However, as a CCS certificate needs to be provided at the handover of the final Code unit, the construction of the private units will not benefit from the CCS registration. The developer felt that having an in-house Code assessor has been essential in understanding and achieving the Code status required in the most cost effective way. This has also ensured that the process of achieving design stage certification and obtaining evidence for the post-construction certification has been easier than for other developers who rely on external assessors. It has allowed a greater control over the end product and has meant that certification is not reliant on an additional third party with other commitments. The site is also located very close to head office, which has meant that site visits could be easily made to keep track of progress and any problems that have arisen. COSTS AND VALUE The build cost excluding land and fees was around £1050 per square meter. The developer estimated that the marginal additional cost/unit to achieve Code Level 3 was £3000–£3500 compared to a standard unit built to Building Regulations. Additional costs, such as those for training, were not specifically quantified but were absorbed into overall costs. This project used a common build system, with which the contractor had previous experience. The developer estimated that these costs would not reduce on future developments (where the design solutions being used at Tempo are being replicated) unless the cost of items such as the solar thermal water heating or photovoltaic cells were reduced. The homes were built for social housing purposes, and were not intended for sale. The private sale value of these properties was estimated at about £200,000 for the flats and £350,000 for the houses, equal to sales values for equivalent properties in the area. CASE STUDY 7 | CODE FOR SUSTAINABLE HOMES | 31
Page 1 and 2: THE CODE FOR SUSTAINABLE HOMES Case
Page 3 and 4: BACKGROUND The Code for Sustainable
Page 5 and 6: CONSTRUCTION AND BUILD SYSTEMS The
Page 7 and 8: Level achieved: low-e double or tri
Page 9 and 10: KEY LESSONS A number of lessons can
Page 11 and 12: CASE STUDY 5 Freshney Green Grimsby
Page 13 and 14: TECHNICAL PERFORMANCE External Fabr
Page 15 and 16: Buyer/Occupant Feedback Of the 40 u
Page 17 and 18: CODE FOR SUSTAINABLE HOMES | 17
Page 19 and 20: CASE STUDY 6 Southcroft Park Stanle
Page 21 and 22: TECHNICAL PERFORMANCE External Fabr
Page 23 and 24: Buyer/Occupant Feedback All of the
Page 25 and 26: CODE FOR SUSTAINABLE HOMES | 25
Page 27 and 28: CASE STUDY 7 TEMPO Palmers Green, L
Page 29: TECHNICAL PERFORMANCE External Fabr
Page 33 and 34: Design Team PERCENTAGE OF CATEGORY
Page 35 and 36: CASE STUDY 8 Miller Zero, Merton Ri
Page 37 and 38: SUSTAINABILITY FEATURES Code Level
Page 39 and 40: WORKING WITH THE CODE FOR SUSTAINAB
Page 41 and 42: CODE LEVEL 3 CODE LEVEL 6 PERCENTAG
Page 43 and 44: CASE STUDY 9 One Earth Homes, Upton
Page 45 and 46: Sensors have been installed into th
Page 47 and 48: WORKING WITH THE CODE FOR SUSTAINAB
Page 49 and 50: Department for Communities and Loca

Code for sustainable homes: case studies volume 2 - Gov.uk

Create successful ePaper yourself

Delete template?

Save as template?